Uremic toxins removal and iron status: a medium-term comparison between 4 dialysis techniques (EMPIRE study)

Recent evidence documented that dialyzers and hemodialytic techniques yield different dialytic performances. The study aims to compare uremic toxins removal and iron status between on-line hemodiafiltration (OL-HDF), high-flux hemodialysis (HF-HD), expanded hemodialysis (HDx), and HFR Aequilibrium (HFR-Aeq). A single-center retrospective observational study enrolled 52 patients on chronic HD. Each study group (HFR-Aeq, HDx, HF-HD, and OL-HDF) included 13 patients. Naïve patients for each of the treatments were considered. Serum samples were collected at baseline and after 12–24–48 weeks from the enrollment. Intragroup comparison was performed using Friedman’s test whereas longitudinal data were compared using linear mixed models (LMMs). HDx showed a progressive improvement in the removal of urea (<i>p</i> = 0.043), λ -free light chains (<i>p</i> = 0.033), and transferrin saturation (<i>p</i> = 0.011) compared to other techniques. A nearly significant slope of β2 M was observed (<i>p</i> = 0.066). Also HFR-Aeq showed a near significant reduction in λ FLC values (<i>p</i> = 0.05) and a nearly significant increase in albumin levels (<i>p</i> = 0.07). HFR-Aeq provides uremic toxins removal comparable to other traditional techniques (HF-HD, OL-HDF). HDx confirmed its superiority in the removal of uremic toxins as urea and λ FLC and surprisingly enhanced TSAT by a possible anti-inflammatory effect not ascertained in the present study. The utilization of non-optimal convective volumes likely vanishes the promising findings of OL-HDF.

现有研究证据表明，不同透析器与血液透析技术的透析效能存在差异。本研究旨在比较在线血液透析滤过（on-line hemodiafiltration, OL-HDF）、高通量血液透析（high-flux hemodialysis, HF-HD）、扩展式血液透析（expanded hemodialysis, HDx）及HFR平衡型透析（HFR Aequilibrium, HFR-Aeq）的尿毒症毒素清除效果与铁代谢状态。本研究为单中心回顾性观察性研究，纳入52例慢性血液透析（chronic HD）患者，各组（HFR-Aeq、HDx、HF-HD及OL-HDF）各纳入13例患者，所有受试者均为对应治疗方案的初治患者。分别于基线及入组后12、24、48周采集血清样本。组内比较采用Friedman检验，纵向数据比较则采用线性混合模型（linear mixed models, LMMs）。与其他透析技术相比，HDx在清除尿素（p=0.043）、λ游离轻链（p=0.033）及转铁蛋白饱和度（p=0.011）方面呈进行性改善；β2微球蛋白（β2M）的清除斜率接近统计学显著性（p=0.066）。此外，HFR-Aeq可使λ游离轻链（λ FLC）水平接近显著性降低（p=0.05），并使白蛋白水平接近显著性升高（p=0.07）。HFR-Aeq的尿毒症毒素清除效果与其他传统透析技术（HF-HD、OL-HDF）相当。HDx证实了其在清除尿素、λ游离轻链等尿毒症毒素方面的优势，且意外发现其可通过潜在抗炎作用提升转铁蛋白饱和度（TSAT），该效应尚未在本研究中得到证实。非最优对流体积的使用可能抵消了OL-HDF原本具有潜力的研究结果。